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Lesson four: Air quality and weather

Air quality is affected by the weather and the shape of the land. This lesson explores why air quality differs in different parts of Aotearoa New Zealand. 

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Did you know that air quality is affected by the weather and the shape of the land?  

On colder winter nights we burn wood in fires, which puts smoke pollution in the air.  

When it’s windy the pollution gets carried away. When there is no wind it sticks around.  

Hills act as a barrier and stop pollution from blowing away. Towns in valleys are sometimes sheltered from the wind and can therefore have very bad air quality in winter.  

During the day, the sun warms up the ground and the ground warms up the nearby air. At night the warm air near the ground gets trapped by clouds. If it is a clear night, the warm air is free to lift upwards. This layer of warm air above the town is called an inversion. The inversion acts as a lid and keeps pollution near the ground, trapped around the town.   

Drainage flow is what we call cold air that sinks down from the tops of hills after cold nights. Drainage flow can trap pollution in from the sides.  

Image: Arrowtown is one example of a town in Aotearoa that has issues with poor air quality due to wood burning on cold, still winter nights. 

Key summary points  

  • Wind can blow smoke pollution away.  
  • The weather and hills can trap smoke pollution in around towns. 

Activity: make a wind sock  

You can make your own windsock with things you can find around the house. 

This website gives instructions with short videos showing how to make both wet and dry windsocks.  

Making a dry windsock is easier but it won't last in the rain like a wet one will.  

Quiz: Air quality and weather 

Check out our air quality quiz over on Kahoot

The quiz works best on Kahoot, but if you prefer a text version, you can download it as a PDF.

Worksheet: Air quality and weather

Download worksheet.


Principal Scientist - Air Quality